This invention relates to implantable prosthetic devices of rod-type construction. In particular, the improved prosthetic device disclosed herein is of the type incorporating a malleable rod which permits the device to be bent between a comfortable, out of the way position and a straight position wherein the penis is held erect for sexual intercourse. Such a penile prosthesis incorporating a malleable rod is disclosed in U.S. Pat. No. 3,987,789 issued on 0ct. 26, 1976 to Gerald W. Timm and John H. Burton.
A variation of the surgically implantable malleable penile prosthesis having a limited bend feature is disclosed in U.S. Pat. No. 4,392,562 issued on July 12, 1983. An implantable penile prosthesis incorporating a stiffening bar having a joint bendable from a straight configuration to a curved position in only one direction is disclosed in U.S. Pat. No. 4,177,805 issued on Dec. 11, 1979 to Theodor Tudoriu. A rod type of penile implant comprised of axial sections of varying flexural properties, and including a very flexible hinge section, is disclosed in U.S. Pat. No. 4,066,073 issued to Roy B. Finney et al. U.S. Pat. No. 4,151,840 issued on May 1, 1979 to James E. Barrington discloses still a further version of a mechanical penile prosthesis which is bendable and is comprised of a series of link members coupled to each other in such a way as to permit the prosthesis to be bent between curved and straight configurations.
The evolution of the bendable and malleable types of implantable penile prostheses followed the rigid rod type of penile prosthesis of U.S. Pat. No. 3,893,456 issued to Michael P. Small et al on July 8, 1975. That type of prosthesis incorporates a rigid rod having flexural stiffness which suffers from the disadvantage of holding the penis in substantially a permanent erectile state. The bendable and malleable penile prosthetic devices overcome that particular shortcoming.
A malleable penile prosthesis manufactured in West Germany by Walter Koss OHG and distributed in the United States by Dacomed Corporation of Minneapolis, Minn. is disclosed in a European patent application filed on Nov. 19, 1981 under Application No. 81109752.6 and bearing a disclosure or publication number of No. 0,052,858. That device incorporates a length adjustment feature achieved by using a malleable cylinder which may be cut to various lengths at predetermined increments in combination with a silicone cover which may be pulled over one end of the cylinder.
The malleable penile prosthesis disclosed herein has been developed with a view towards providing a means for readily adjusting the diameter of the implant cylinder to accommodate the physical anatomy of particular patients. Also, the potential problem of damaging the silicone rubber cylinder by the abrading action of a metallic malleable rod encased therein has been overcome by utilizing a special protective sheath around the malleable rod as disclosed herein.